The invention relates to a lifting apparatus, and more particularly, a lifting apparatus for engaging, lifting, moving, and lowering manhole castings and the like.
During the excavation and reconstruction of roads, buildings, and parking lots, it is necessary to remove, manipulate, and replace manhole covers and similar grates. These various manhole covers and grates may weigh anywhere between 300 to 600 pounds. Traditionally, several laborers would attempt to lift and move these manhole covers and grates in proper position. However, the extreme weight and bulkiness of these manhole covers and grates places such laborers at risk of injury since there is no good way to lift such heavy and bulky objects either manually or by machine.
Manhole covers and grates, as well as other related items, come in a variety of shapes and sizes. It is desirable to be able to lift these elements with one simple device that is adaptable to a wide range of construction equipment found at a construction site. Previous devices have provided adjustable mechanisms using multiple pieces and pins to lock the pieces into position. These devices lack the durability and practicality required for a construction site. The pins and extended members typically break or are lost when used and stored about a construction site.
It would be desirable to provide a lifting apparatus that was simple and durable while also providing for a certain degree of adjustment. In addition, it would also be desirable to provide a lifting apparatus that could be utilized in conjunction with a lifting device so that laborers would not be required to manually lift heavy objects and the like.
The present invention relates to a lifting apparatus for manipulating manhole castings and the like. The lifting apparatus preferably provides at least one pinch clamp having an inner leg and an outer leg opposing one another wherein the inner leg and the outer leg are engageable with a manhole casting. A foot on the pinch clamp is connected to at least one of the inner legs and the outer legs wherein the foot is wider than the width of the inner leg and the outer leg and is engageable with the manhole casting. A flexible support is pivotally connected to the pinch clamp and connectable to a lifting device wherein the foot and the inner and outer legs of the pinch clamp are engageable with the manhole casting when the flexible support is pulled taut by the lifting device. A connector is pivotally connected to the flexible support and connectable to the lifting device.
In the preferred embodiment, the inner leg and the outer leg of the pinch clamp are independent, substantially parallel structures pivotally connected about a pivotal axis. The inner and outer legs pivot in a plane substantially normal to the pivotal axis. In an alternative embodiment, the inner and outer legs are integrally fabricated to form a substantially C-shaped, one-piece structure.
In yet another embodiment, a multipurpose hook is pivotally connected to the end of the second flexible support member the second flexible support is pivotally connected to the connector.